From owner-chemistry@ccl.net Tue Apr 23 07:18:00 2013 From: "bonoit bonoit bonoit_10-,-yahoo.fr" To: CCL Subject: CCL: Spin contamination Message-Id: <-48590-130423071639-18662-UEV7XlG0nNEERBhDeWTEiQ|a|server.ccl.net> X-Original-From: "bonoit bonoit" Date: Tue, 23 Apr 2013 07:16:38 -0400 Sent to CCL by: "bonoit bonoit" [bonoit_10(~)yahoo.fr] Dear CCLers, I've an inquiry about spin contamination (UHF method for example) when working on open shell molecules. In books, they said that the origin of this phenomenun is the next high spin state which is mixed with the desired one. Could someone tell me the explanation of that and where it is originated from, please? With the best wishes Bonoit From owner-chemistry@ccl.net Tue Apr 23 08:39:00 2013 From: "Georg Lefkidis lefkidis-.-physik.uni-kl.de" To: CCL Subject: CCL: Spin contamination Message-Id: <-48591-130423083740-12912-0z2cWblRgW9YatZV2gO1pA * server.ccl.net> X-Original-From: "Georg Lefkidis" Content-Language: de Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="iso-8859-1" Date: Tue, 23 Apr 2013 14:37:28 +0200 MIME-Version: 1.0 Sent to CCL by: "Georg Lefkidis" [lefkidis%a%physik.uni-kl.de] Dear Bonoit, only restricted HF calculations can be pure spins (that is eigenstates of the spin operator) because per construction that can only happen if the molecular orbitals for the alpha and beta electrons are identical (can but must not necessarily). Since this prerequisite is not met by UHF there is spin contamination. This contamination is typically admixtures from higher rather than lower multiplicities. The reason for this is that if the orbitals are not identical, then if you project the one set onto the other (say the beta orbitals onto the alpha ones) you get different occupancies (in fact partial occupations) which practically describe more unpaired electrons than your intention. Hence you end up with higher multiplicity. Mind though, that for high multiplicities you can get contamination from lower multiplicities as well. However the overall spin expectation value is in reality always higher (at least I've never seen something else), since very high multiplicities means many more alpha than beta electrons, which, in turn, leads to stronger deviations of the two orbital sets. So in summary I'd say, spin contamination means no pure spin eigenstates anymore. Projection to pure spin states gives a admixtures from series of different pure spins, and the expectation value of the spin (not eigenvalue) ends up being higher due to orthogonality issues between the two orbital sets. Best regards George -----Ursprüngliche Nachricht----- Von: owner-chemistry+lefkidis==physik.uni-kl.de * ccl.net [mailto:owner-chemistry+lefkidis==physik.uni-kl.de * ccl.net] Im Auftrag von bonoit bonoit bonoit_10-,-yahoo.fr Gesendet: Dienstag, 23. April 2013 13:17 An: Lefkidis, Georg Betreff: CCL: Spin contamination Sent to CCL by: "bonoit bonoit" [bonoit_10(~)yahoo.fr] Dear CCLers, I've an inquiry about spin contamination (UHF method for example) when working on open shell molecules. In books, they said that the origin of this phenomenun is the next high spin state which is mixed with the desired one. Could someone tell me the explanation of that and where it is originated > from, please? With the best wishes Bonoithttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt From owner-chemistry@ccl.net Tue Apr 23 09:20:00 2013 From: "Christopher Cramer cramer:-:umn.edu" To: CCL Subject: CCL: Spin contamination Message-Id: <-48592-130423085119-18196-giX5Lua7hbwF+i/9DZMjYQ##server.ccl.net> X-Original-From: Christopher Cramer Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=us-ascii Date: Tue, 23 Apr 2013 07:51:09 -0500 Mime-Version: 1.0 (Apple Message framework v1085) Sent to CCL by: Christopher Cramer [cramer]^[umn.edu] Bonoit, For a particularly succinct picture of why spin contamination enters as a consequence of dynamical correlation, see slide numbered 13 of http://pollux.chem.umn.edu/8021/Lectures/OpenShell_8.pdf for which Thomas Bally of the University of Fribourg deserves credit (by the way, haters, that's not Comic Sans, honest!) You can also watch a video narrating the relevant slides, grouped as IV.vii, at http://pollux.chem.umn.edu/8021/Lectures/ Best, Chris On Apr 23, 2013, at 6:16 AM, bonoit bonoit bonoit_10-,-yahoo.fr wrote: > > Sent to CCL by: "bonoit bonoit" [bonoit_10(~)yahoo.fr] > Dear CCLers, > > I've an inquiry about spin contamination (UHF method for example) when working on open shell molecules. In books, they said that the origin of this phenomenun is the next high spin state which is mixed with the desired one. > Could someone tell me the explanation of that and where it is originated from, please? > > With the best wishes > > Bonoit> > -- Christopher J. Cramer Elmore H. Northey Professor University of Minnesota Department of Chemistry 207 Pleasant St. SE Minneapolis, MN 55455-0431 Phone: (612) 624-0859 || FAX: (612) 626-7541 -------------------------- Faculty Liaison for eLearning Initiatives Office of the Senior Vice President for Academic Affairs and Provost 236 Morrill Hall Phone: (612) 626-1215 -------------------------- Mobile: (952) 297-2575 Email: cramer|,|umn.edu Twitter: |,|ChemProfCramer Website: http://pollux.chem.umn.edu From owner-chemistry@ccl.net Tue Apr 23 18:11:00 2013 From: "Adel El-Azhary azhary=-=KSU.EDU.SA" To: CCL Subject: CCL: AMD vs for computing Message-Id: <-48593-130422040717-15409-dI/TWcPS7EK556KuJCIj9w]_[server.ccl.net> X-Original-From: Adel El-Azhary Content-Language: en-US Content-Type: multipart/alternative; boundary="_000_285418da94e1430cb52a257be0b5e37bEXMBX02KSULOCAL_" Date: Mon, 22 Apr 2013 08:07:04 +0000 MIME-Version: 1.0 Sent to CCL by: Adel El-Azhary [azhary###KSU.EDU.SA] --_000_285418da94e1430cb52a257be0b5e37bEXMBX02KSULOCAL_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Deat John, Please notice that the AMD processor is cheaper. You also talk about proces= sors. But how many cores each processor has. Usually the AMD processor have= more cores. Also notice that the Intel processor has two nodes and the AMD= processor is only one node. But my experience is that this two nodes for t= he Intel processor for each core does not work. I mean you have to consider= the Intel processor as if it is only one node per core. I hope this helps. Best regards, Adel El-Azhary ________________________________ > From: owner-chemistry+azhary=3D=3Dksu.edu.sa[#]ccl.net on behalf of John McKe= lvey jmmckel:-:gmail.com Sent: Monday, April 22, 2013 2:32 AM To: Adel El-Azhary Subject: CCL: AMD vs for computing Folks, The AMD 8 proc 8350 and the Intel 3770 4 proc have the about the same para= llel PASSMARK values (Intel less than 10% faster). Thoughts about choosing the AMD over the Intel, ignoring the diifference in= PASSMARK scores? John -- John McKelvey 10819 Middleford Pl Ft Wayne, IN 46818 260-489-2160 jmmckel.:.gmail.com ________________________________ Disclaimer: This communication is intended for the above named person and is confidenti= al and / or legally privileged. Any opinion(s) expressed in this communicat= ion are not necessarily those of KSU (King Saud University). If it has come= to you in error you must take no action based upon it, nor must you print = it, copy it, forward it, or show it to anyone. Please delete and destroy th= e e-mail and any attachments and inform the sender immediately. Thank you. KSU is not responsible for the political, religious, racial or partisan opi= nion in any correspondence conducted by its domain users. Therefore, any su= ch opinion expressed, whether explicitly or implicitly, in any said corresp= ondence is not to be interpreted as that of KSU. KSU may monitor all incoming and outgoing e-mails in line with KSU business= practice. Although KSU has taken steps to ensure that e-mails and attachme= nts are free from any virus, we advise that, in keeping with best business = practice, the recipient must ensure they are actually virus free. --_000_285418da94e1430cb52a257be0b5e37bEXMBX02KSULOCAL_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Deat John,

 

Please notice that the AMD processor is cheap= er. You also talk about processors. But how many cores each processor has. = Usually the AMD processor have more cores. Also notice that the Intel processor has two nodes and the AMD processor is only one node. = But my experience is that this two nodes for the Intel processor for each c= ore does not work. I mean you have to consider the Intel processor as if it= is only one node per core. I hope this helps.

Best regards,

 

Adel El-Azhary


From: owner-chemistry+a= zhary=3D=3Dksu.edu.sa[#]ccl.net on behalf of John McKelvey jmmckel:-:gmail.co= m
Sent: Monday, April 22, 2013 2:32 AM
To: Adel El-Azhary
Subject: CCL: AMD vs for computing
 
Folks,

The AMD 8 proc 8350  and the Intel 3770 4 proc have the about the same= parallel PASSMARK values (Intel less than 10% faster). 

Thoughts about choosing the AMD over the Intel, ignoring the diifference in= PASSMARK scores?

John

--
John McKelvey
10819 Middleford Pl
Ft Wayne, IN 46818
260-489-2160
jmmckel.:.gmail.com



Disclaimer:
This communication is intended for the above named person and is confidenti= al and / or legally privileged. Any opinion(s) expressed in this communicat= ion are not necessarily those of KSU (King Saud University). If it has come= to you in error you must take no action based upon it, nor must you print it, copy it, forward it, or show = it to anyone. Please delete and destroy the e-mail and any attachments and = inform the sender immediately. Thank you.
KSU is not responsible for the political, religious, racial or partisan opi= nion in any correspondence conducted by its domain users. Therefore, any su= ch opinion expressed, whether explicitly or implicitly, in any said corresp= ondence is not to be interpreted as that of KSU.
KSU may monitor all incoming and outgoing e-mails in line with KSU business= practice. Although KSU has taken steps to ensure that e-mails and attachme= nts are free from any virus, we advise that, in keeping with best business = practice, the recipient must ensure they are actually virus free.
--_000_285418da94e1430cb52a257be0b5e37bEXMBX02KSULOCAL_-- From owner-chemistry@ccl.net Tue Apr 23 22:18:01 2013 From: "John McKelvey jmmckel .. gmail.com" To: CCL Subject: CCL: AMD vs for computing Message-Id: <-48594-130423205232-3808-rTEd6iMaa+auc+9fsk6PFw,+,server.ccl.net> X-Original-From: John McKelvey Content-Type: multipart/alternative; boundary=089e0122e8dc26c43504db10b786 Date: Tue, 23 Apr 2013 20:52:25 -0400 MIME-Version: 1.0 Sent to CCL by: John McKelvey [jmmckel||gmail.com] --089e0122e8dc26c43504db10b786 Content-Type: text/plain; charset=ISO-8859-1 Adel, I agree with your analysis... The extra ones have to borrow from the main 4. I think that the I7 is decent for a server in a business where transactions are short. I'm looking for a reliable source for a mobo setup for an AMD setup. John On Mon, Apr 22, 2013 at 4:07 AM, Adel El-Azhary azhary=-=KSU.EDU.SA < owner-chemistry%%ccl.net> wrote: > Deat John, > > > > Please notice that the AMD processor is cheaper. You also talk about > processors. But how many cores each processor has. Usually the AMD > processor have more cores. Also notice that the Intel processor has two > nodes and the AMD processor is only one node. But my experience is that > this two nodes for the Intel processor for each core does not work. I mean > you have to consider the Intel processor as if it is only one node per > core. I hope this helps. > > Best regards, > > > > Adel El-Azhary > > ------------------------------ > *From:* owner-chemistry+azhary==ksu.edu.sa---ccl.net on behalf of John > McKelvey jmmckel:-:gmail.com > *Sent:* Monday, April 22, 2013 2:32 AM > *To:* Adel El-Azhary > *Subject:* CCL: AMD vs for computing > > Folks, > > The AMD 8 proc 8350 and the Intel 3770 4 proc have the about the same > parallel PASSMARK values (Intel less than 10% faster). > > Thoughts about choosing the AMD over the Intel, ignoring the diifference > in PASSMARK scores? > > John > > -- > John McKelvey > 10819 Middleford Pl > Ft Wayne, IN 46818 > 260-489-2160 > jmmckel.:.gmail.com > > ------------------------------ > > Disclaimer: > This communication is intended for the above named person and is > confidential and / or legally privileged. Any opinion(s) expressed in this > communication are not necessarily those of KSU (King Saud University). If > it has come to you in error you must take no action based upon it, nor must > you print it, copy it, forward it, or show it to anyone. Please delete and > destroy the e-mail and any attachments and inform the sender immediately. > Thank you. > KSU is not responsible for the political, religious, racial or partisan > opinion in any correspondence conducted by its domain users. Therefore, any > such opinion expressed, whether explicitly or implicitly, in any said > correspondence is not to be interpreted as that of KSU. > KSU may monitor all incoming and outgoing e-mails in line with KSU > business practice. Although KSU has taken steps to ensure that e-mails and > attachments are free from any virus, we advise that, in keeping with best > business practice, the recipient must ensure they are actually virus free. > -- John McKelvey 10819 Middleford Pl Ft Wayne, IN 46818 260-489-2160 jmmckel%%gmail.com --089e0122e8dc26c43504db10b786 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Adel,

I agree with your analys= is...=A0 The extra ones have to borrow from the main 4.=A0 I think that the= I7 is decent for a server in=A0 a business where transactions are short.
I'm looking for a reliable source for a mobo setup for an AMD set= up.

John


On Mon, Apr 22, 2013 at 4:07 AM, Adel El-Azhary azhary=3D= -=3DKSU.EDU.SA <owner-chemistry%%cc= l.net> wrote:

Deat John,

=A0

P= lease notice that the AMD processor is cheaper. You also talk about process= ors. But how many cores each processor has. Usually the AMD processor have = more cores. Also notice that the Intel processor has two nodes and the AMD processor is only one node. = But my experience is that this two nodes for the Intel processor for each c= ore does not work. I mean you have to consider the Intel processor as if it= is only one node per core. I hope this helps.

Best regards,

=A0

Adel El-Azhary


From: owner-chemistry+azhary=3D=3Dksu.edu.sa---ccl.net on beh= alf of John McKelvey jmmckel:-:gmail.com
Sent: Monday, April 22, 2013 2:32 AM
To: Adel El-Azhary
Subject: CCL: AMD vs for computing
=A0
Folks,

The AMD 8 proc 8350=A0 and the Intel 3770 4 proc have the about the same pa= rallel PASSMARK values (Intel less than 10% faster).=A0

Thoughts about choosing the AMD over the Intel, ignoring the diifference in= PASSMARK scores?

John

--
John McKelvey
10819 Middleford Pl
Ft Wayne, IN 46818
260-4= 89-2160
jmmckel.:.gmail.co= m



Disclaimer:
This communication is intended for the above named person and is confidenti= al and / or legally privileged. Any opinion(s) expressed in this communicat= ion are not necessarily those of KSU (King Saud University). If it has come= to you in error you must take no action based upon it, nor must you print it, copy it, forward it, or show = it to anyone. Please delete and destroy the e-mail and any attachments and = inform the sender immediately. Thank you.
KSU is not responsible for the political, religious, racial or partisan opi= nion in any correspondence conducted by its domain users. Therefore, any su= ch opinion expressed, whether explicitly or implicitly, in any said corresp= ondence is not to be interpreted as that of KSU.
KSU may monitor all incoming and outgoing e-mails in line with KSU business= practice. Although KSU has taken steps to ensure that e-mails and attachme= nts are free from any virus, we advise that, in keeping with best business = practice, the recipient must ensure they are actually virus free.



--
John McKelvey
10819 = Middleford Pl
Ft Wayne, IN 46818
260-489-2160
jmmckel%%gmail.com
--089e0122e8dc26c43504db10b786--